Abstract
Lateral loading tests on pile groups of four and nine piles arranged on square grids were performed using a model ground of cohesive soil, which resulted in large deformation of piles. In addition, lateral loading tests on a single pile were also performed in order to clarify the efficiency of pile groups. Based on the results, the load burden ratio for each row of grouped piles was calculated, and the large lateral deformation behavior of the piles was studied. It was found that the group of four piles was more significantly affected by the ground strength than the group of nine piles. Furthermore, empirical equations to derive the efficiency of pile groups were proposed based on the footing displacement ratio, number of piles in a group, and relative rigidity between the ground and piles.
